Equity and Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Apr. 27, 2019	Jan. 26, 2019	Oct. 27, 2018	Jul. 28, 2018	Apr. 28, 2018	Jan. 27, 2018	Oct. 28, 2017	Jul. 29, 2017	Apr. 27, 2019	Apr. 28, 2018	Apr. 29, 2017	Dec. 14, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount									2,939,089	2,494,799	375,457
Common Stock, Shares Authorized	200,000,000				200,000,000				200,000,000	200,000,000
Common Stock, Par or Stated Value Per Share	$ 0.01				$ 0.01				$ 0.01	$ 0.01
Preferred Stock, Shares Authorized	5,000,000				5,000,000				5,000,000	5,000,000
Preferred Stock, Par or Stated Value Per Share	$ 0.01				$ 0.01				$ 0.01	$ 0.01
Common Stock, Shares, Outstanding	47,562,947				46,917,000				47,562,947	46,917,000
Preferred Stock, Shares Outstanding	0				0				0	0
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	10,409,345								10,409,345
Stock Repurchase Program, Authorized Amount												$ 50,000
Stock Repurchased During Period, Shares											689,000
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 26,669								$ 26,669
Treasury Stock Acquired, Average Cost Per Share											$ 10.10
Shares Paid for Tax Withholding for Share Based Compensation									351,043	260,531	276,292
Net Income (Loss) Attributable to Parent	$ (46,218)	$ 769	$ 59,697	$ (38,622)	$ 17,057	$ (283,235)	$ 48,395	$ (34,783)	$ (24,374)	$ (252,566)	$ 5,361
Undistributed Earnings (Loss) Allocated to Participating Securities, Basic									0	0	3
Net Income (Loss) Available to Common Stockholders, Basic									(24,374)	(252,566)	5,358
Undistributed Earnings, Basic									0	0	3
Undistributed Earnings (Loss) Allocated to Participating Securities, Diluted									0	0	3
Net Income (Loss) Available to Common Stockholders, Diluted									$ (24,374)	$ (252,566)	$ 5,358
Weighted Average Number of Shares Outstanding, Basic									47,306,000	46,763,000	46,317,000
Average dilutive restricted stock units									0	0	389,000
Average dilutive performance shares									0	0	40,000
Average dilutive restricted shares									0	0	17,000
Average Dilutive Options									0	0	0
Average Dilutive Performance Share Units									0	0	0
Weighted Average Number of Shares Outstanding, Diluted									47,306,000	46,763,000	46,763,000
Earnings Per Share, Basic	$ (0.97)	$ 0.02	$ 1.26	$ (0.82)	$ 0.36	$ (6.04)	$ 1.04	$ (0.75)	$ (0.52)	$ (5.40)	$ 0.12
Earnings Per Share, Diluted	$ (0.97)	$ 0.02	$ 1.25	$ (0.82)	$ 0.36	$ (6.04)	$ 1.03	$ (0.75)	$ (0.52)	$ (5.40)	$ 0.11
Treasury Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Stock Repurchased During Period, Value											$ 6,718
Shares Paid for Tax Withholding for Share Based Compensation									352,000	260,000